Screen printing is a versatile and universally usable printing process. The screen printing inks used must of course be adapted to the particular application and to the printed substrate. Like any printing inks, lacquers and coating compositions, screen printing inks contain many components which may be roughly divided into volatile and non-volatile.
The non-volatile components include binders, pigments, fillers and auxiliaries which, in most cases, are only needed in very small quantities for problem-free processing, but are nevertheless indispensable. The volatile constituents are essentially organic solvents and also water. The non-volatile binders ensure that the ink is anchored to the substrate so that the final print withstands the effects of abrasion, heat and mechanical distortion.
Accordingly, the binders required (for example for the abrasion-resistant surface modification of injection-molded articles by insert molding) should not melt at the high temperatures used for injection molding, should adhere firmly to the substrate and should be flexible. These requirements are satisfied by special highly heat-resistant polycarbonates.